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<p>做电路绕不开电阻电容这对好兄弟</p>
</blockquote>
<p>（仍在施工中ing）</p>
<h1 id="电容工艺"><a href="#电容工艺" class="headerlink" title="电容工艺"></a>电容工艺</h1><h2 id="非极性电容"><a href="#非极性电容" class="headerlink" title="非极性电容"></a>非极性电容</h2><p>大都是<strong>MLCC</strong>（多层陶瓷电容），注意封装不单影响大小，还影响耐压。0402耐压值较低（队里一本电容本0402 1uF 耐压只有10V，而6.8nF耐压有50V，另一本的10nF也有50V耐压），建议只用在5V及以下电源电路中 。1210 耐压高点。</p>
<h2 id="电解电容"><a href="#电解电容" class="headerlink" title="电解电容"></a>电解电容</h2><p>电解电容具有极性，但为什么有极性我尚不明白<sup id="fnref:1"><a href="#fn:1" rel="footnote"><span class="hint--top hint--error hint--medium hint--rounded hint--bounce" aria-label="警告：这玩意随时有可能爆炸
">[1]</span></a></sup>。<br><strong>钽电容：</strong> 黄色封装，注意封装上的标记是<strong>正极</strong>！充放电快，ESR小。<br><strong>铝电容：</strong> 块头较大，充放电慢，ESR大，但容值会大。</p>
<h1 id="电容功能"><a href="#电容功能" class="headerlink" title="电容功能"></a>电容功能</h1><p>根据连接方式的不同，串联作为隔直功能，并联作为去耦、旁路功能</p>
<h1 id="隔直电容-Blocking"><a href="#隔直电容-Blocking" class="headerlink" title="隔直电容(Blocking)"></a>隔直电容(Blocking)</h1><p>去除直流成分消除直流偏置<br>特别是多级放大电路中，直流偏置会越放越大，隔直电容不可缺少<br>因此要容值偏大，降低对需要的交流信号的衰减作用</p>
<h2 id="去耦电容-Decoupling"><a href="#去耦电容-Decoupling" class="headerlink" title="去耦电容(Decoupling)"></a>去耦电容(Decoupling)</h2><p>降低IC对电源的影响</p>
<h2 id="旁路电容-Bypass"><a href="#旁路电容-Bypass" class="headerlink" title="旁路电容(Bypass)"></a>旁路电容(Bypass)</h2><p>降低电源对IC的影响</p>
<p>并联在传输线上，高频的噪声通过旁路电容流掉，达到滤噪声的目的。一般使用<strong>一个大电容并联一个小电容</strong></p>
<p>但是大电容和小电容并联等效容值相加，那么为什么不用一个更大容值的电容代替呢？</p>
<p>原来是由于制造工艺的原因，大容值的电容往往带有较大的感抗，高频特性反而不好，常常采用一大电容，一小电容并联的形式去去掉高频噪声<sup id="fnref:2"><a href="#fn:2" rel="footnote"><span class="hint--top hint--error hint--medium hint--rounded hint--bounce" aria-label="这里分析电容模型时，应当将电容看作RLC串联，至于为什么是串联，我尚不明白
">[2]</span></a></sup><br><img src="Impendance.png" alt="常见MLCC电容阻抗曲线"><br>RLC串联回路工作在谐振频率时，电路的阻抗最小，此时对信号的衰减效果最小<sup id="fnref:3"><a href="#fn:3" rel="footnote"><span class="hint--top hint--error hint--medium hint--rounded hint--bounce" aria-label="所以选择电容时要注意电容的谐振频率
">[3]</span></a></sup></p>
<p>频率到达谐振点之前，电容呈现容性，频率到达谐振点之后，电容呈现感性。<br>容值越大的电容谐振频率越低，高频特性越不好。不过似乎呈现感性时，在一定的频率，电容的阻抗大小几乎和容值参数没关系，并联是为了降低阻抗，为什么要并联一个容值更小的电容呢？<sup id="fnref:4"><a href="#fn:4" rel="footnote"><span class="hint--top hint--error hint--medium hint--rounded hint--bounce" aria-label="未考虑相位的影响，不过滤噪声似乎不需要考虑这个？也可能从成本的角度或者这个图并不详尽。">[4]</span></a></sup></p>
<p>对于47uF的电容，谐振频率在1MHz左右，一般使用MLCC用不到这么大的，谐振频率更高，对于低频电路不需要考虑感抗问题。</p>
<p>在<a target="_blank" rel="noopener" href="https://ds.murata.co.jp/simsurfing/mlcc.html?lcid=zh-cn">该网站</a>可以查询常见MLCC电容的参数曲线。</p>
<h1 id="参考文献"><a href="#参考文献" class="headerlink" title="参考文献"></a>参考文献</h1><p><a target="_blank" rel="noopener" href="https://en.wikipedia.org/wiki/Electrolytic_capacitor">Electrolytic capacitor - Wikipedia</a></p>
<p><a target="_blank" rel="noopener" href="https://blog.csdn.net/handsomewangjg/article/details/47913775">旁路电容为何通常由一大一小两个电容并联<em>handsomewangggg的博客-CSDN博客</em>为什么滤波电容的电容值是一大一小</a></p>
<p><a target="_blank" rel="noopener" href="https://blog.csdn.net/weixin_42005993/article/details/106504091"> 陶瓷电容的ESR-谐振频率去哪儿查？_硬件工程师炼成之路的博客-CSDN博客</a></p>
<div id="footnotes"><hr><div id="footnotelist"><ol style="list-style: none; padding-left: 0; margin-left: 40px"><li id="fn:1"><span style="display: inline-block; vertical-align: top; padding-right: 10px; margin-left: -40px">1.</span><span style="display: inline-block; vertical-align: top; margin-left: 10px;">警告：这玩意随时有可能爆炸<a href="#fnref:1" rev="footnote"> ↩</a></span></li><li id="fn:2"><span style="display: inline-block; vertical-align: top; padding-right: 10px; margin-left: -40px">2.</span><span style="display: inline-block; vertical-align: top; margin-left: 10px;">这里分析电容模型时，应当将电容看作RLC串联，至于为什么是串联，我尚不明白<a href="#fnref:2" rev="footnote"> ↩</a></span></li><li id="fn:3"><span style="display: inline-block; vertical-align: top; padding-right: 10px; margin-left: -40px">3.</span><span style="display: inline-block; vertical-align: top; margin-left: 10px;">所以选择电容时要注意电容的谐振频率<a href="#fnref:3" rev="footnote"> ↩</a></span></li><li id="fn:4"><span style="display: inline-block; vertical-align: top; padding-right: 10px; margin-left: -40px">4.</span><span style="display: inline-block; vertical-align: top; margin-left: 10px;">未考虑相位的影响，不过滤噪声似乎不需要考虑这个？也可能从成本的角度或者这个图并不详尽。<a href="#fnref:4" rev="footnote"> ↩</a></span></li></ol></div></div></article><div class="tag_share"><div class="post-meta__tag-list"><a class="post-meta__tags" href="/tags/%E7%94%B5%E5%AE%B9/">电容</a></div><div class="post_share"><div class="social-share" data-image="/linear-gradient(20deg,#334d50,#cbcaa5)" data-sites="facebook,twitter,wechat,weibo,qq"></div><link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/butterfly-extsrc/sharejs/dist/css/share.min.css" media="print" onload="this.media='all'"><script src="https://cdn.jsdelivr.net/npm/butterfly-extsrc/sharejs/dist/js/social-share.min.js" defer></script></div></div><div class="post-reward"><div class="reward-button"><i class="fas fa-qrcode"></i> Donate</div><div class="reward-main"><ul class="reward-all"><li class="reward-item"><a href="/img/Wechat.jpg" target="_blank"><img class="post-qr-code-img" src="/img/Wechat.jpg" alt="wechat"/></a><div class="post-qr-code-desc">wechat</div></li></ul></div></div><hr/><div id="post-comment"><div class="comment-head"><div class="comment-headline"><i class="fas fa-comments fa-fw"></i><span> Comment</span></div></div><div class="comment-wrap"><div><div id="lv-container" data-id="city" data-uid="MTAyMC81NzU3OS8zNDA0Mw=="></div></div></div></div></div><div class="aside-content" id="aside-content"><div class="sticky_layout"><div class="card-widget" id="card-toc"><div class="item-headline"><i class="fas fa-stream"></i><span>Catalog</span><span class="toc-percentage"></span></div><div class="toc-content"><ol class="toc"><li class="toc-item toc-level-1"><a class="toc-link" href="#%E7%94%B5%E5%AE%B9%E5%B7%A5%E8%89%BA"><span class="toc-number">1.</span> <span class="toc-text">电容工艺</span></a><ol class="toc-child"><li class="toc-item toc-level-2"><a class="toc-link" href="#%E9%9D%9E%E6%9E%81%E6%80%A7%E7%94%B5%E5%AE%B9"><span class="toc-number">1.1.</span> <span class="toc-text">非极性电容</span></a></li><li class="toc-item toc-level-2"><a class="toc-link" href="#%E7%94%B5%E8%A7%A3%E7%94%B5%E5%AE%B9"><span class="toc-number">1.2.</span> <span class="toc-text">电解电容</span></a></li></ol></li><li class="toc-item toc-level-1"><a class="toc-link" href="#%E7%94%B5%E5%AE%B9%E5%8A%9F%E8%83%BD"><span class="toc-number">2.</span> <span class="toc-text">电容功能</span></a></li><li class="toc-item toc-level-1"><a class="toc-link" href="#%E9%9A%94%E7%9B%B4%E7%94%B5%E5%AE%B9-Blocking"><span class="toc-number">3.</span> <span class="toc-text">隔直电容(Blocking)</span></a><ol class="toc-child"><li class="toc-item toc-level-2"><a class="toc-link" href="#%E5%8E%BB%E8%80%A6%E7%94%B5%E5%AE%B9-Decoupling"><span class="toc-number">3.1.</span> <span class="toc-text">去耦电容(Decoupling)</span></a></li><li class="toc-item toc-level-2"><a class="toc-link" href="#%E6%97%81%E8%B7%AF%E7%94%B5%E5%AE%B9-Bypass"><span class="toc-number">3.2.</span> <span class="toc-text">旁路电容(Bypass)</span></a></li></ol></li><li class="toc-item toc-level-1"><a class="toc-link" href="#%E5%8F%82%E8%80%83%E6%96%87%E7%8C%AE"><span class="toc-number">4.</span> <span class="toc-text">参考文献</span></a></li></ol></div></div></div></div></main><footer id="footer"><div id="footer-wrap"><div class="copyright">&copy;2022 - 2023 By 杜书丞</div><div class="framework-info"><span>Framework </span><a target="_blank" rel="noopener" href="https://hexo.io">Hexo</a><span class="footer-separator">|</span><span>Theme </span><a target="_blank" rel="noopener" href="https://github.com/jerryc127/hexo-theme-butterfly">Butterfly</a></div></div></footer></div><div id="rightside"><div id="rightside-config-hide"><button id="readmode" type="button" title="Read Mode"><i class="fas fa-book-open"></i></button><button id="darkmode" type="button" title="Toggle Between Light And Dark Mode"><i class="fas fa-adjust"></i></button><button id="hide-aside-btn" type="button" title="Toggle between single-column and double-column"><i class="fas fa-arrows-alt-h"></i></button></div><div id="rightside-config-show"><button id="rightside_config" type="button" title="Setting"><i class="fas fa-cog fa-spin"></i></button><button class="close" id="mobile-toc-button" type="button" title="Table Of Contents"><i class="fas fa-list-ul"></i></button><a id="to_comment" href="#post-comment" title="Scroll To Comments"><i class="fas fa-comments"></i></a><button id="go-up" type="button" title="Back To Top"><i class="fas fa-arrow-up"></i></button></div></div><div><script src="/js/utils.js"></script><script src="/js/main.js"></script><script src="https://cdn.jsdelivr.net/npm/@fancyapps/ui/dist/fancybox.umd.min.js"></script><div class="js-pjax"><script>(() => {
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